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Improved Water Injection Index Curve on Estimation of Oil in Place for Fractured Vuggy Carbonate Reservoirs
Fan Haijun,
Kang Zhijiang,
Zheng Songqing,
Zhu Guiliang
Issue:
Volume 8, Issue 6, November 2020
Pages:
124-129
Received:
15 October 2020
Accepted:
26 October 2020
Published:
4 November 2020
Abstract: Fractured vuggy carbonate reservoirs play an important role in the world crude oil resources. The significant reservoir heterogeneity represented by complex distribution of multi-scale fractures and vugs brings challenges to reservoir oil in place (OIP) estimation, which is a fundamental parameter in oil field development. OIP estimation based on production dynamic analysis is regularly carried out in oilfield practice, the result of which is normally adopted as a comparison to volumetric calculation from geological study for mutual verification. This paper introduces a widely used water injection index curve method on OIP estimation of fractured vuggy carbonate reservoir in Tarim oilfield, which is a straight forward plot of bottom-hole pressure versus cumulative water injection. An improved model taking into consideration the compressibility of second gas gap is presented and applied on real well from Tahe carbonate reservoir. The application of the new model demonstrated that conventional method tends to over-estimate the OIP, while the improved model gives a relatively reliable estimation. The improved water injection index curve in this paper is easy to be conducted based on well production and injection dynamic and shows advantages on convenient pressure conversion from well-head to well-bottom and avoiding dealing with the high uncertainty of aquifers in carbonate reservoir.
Abstract: Fractured vuggy carbonate reservoirs play an important role in the world crude oil resources. The significant reservoir heterogeneity represented by complex distribution of multi-scale fractures and vugs brings challenges to reservoir oil in place (OIP) estimation, which is a fundamental parameter in oil field development. OIP estimation based on p...
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Discussed on a New Form of Resistivity Response Equation for Sandstone
Yang Kebing,
Liu Huan,
Cao Cheng Cheng,
Wu Xiaoning
Issue:
Volume 8, Issue 6, November 2020
Pages:
130-136
Received:
19 October 2020
Accepted:
29 October 2020
Published:
9 November 2020
Abstract: The resistivity response equation of sandstone is the most important basis for well logging interpretation to determine the water saturation of reservoir, but the Archie formula and its derivations are all empirical formulas, and the test error by experimental data is more than 20%. Because the coincidence rate of the log interpretation of low resistivity oil layers and high resistivity water layers is low in the current, In order to further improve the calculation accuracy of reservoir water saturation, it is particularly necessary to deeply understand the essence of rock conductivity. Based on the main influencing factors of rock conductivity, It is considered that for rocks with given formation water resistivity and porosity, the influence of pore structure, size, argillaceous content and conductive minerals on rock conductivity is constant and is an inherent factor. rock resistivity only changes with the change of connected pore water volume, Therefore, the establishment of the relationship between rock resistivity and connected pore water volume conforms to the functional relationship form of dependent variable and independent variable, and can reflect the nature of the rock-electricity relationship. On this basis, the model of rock conductivity per unit volume is proposed, the response equation of sandstone resistivity is deduced, and the general form of the response equation of sandstone resistivity is obtained. The results show that the formula is in good agreement with the experimental data, with a correlation coefficient of more than 0.99, and the test error of the experimental data is no more than 5%, which can represent the theoretical form of the rock resistivity response equation. The new formula considers that rock resistivity and connected pore water volume or water saturation are power functions, which solves some obscure problems in rock resistivity response equation for many years. The parameters of the formula are the inherent property parameters of rocks, which have certain value in use. Based on the new formula, the formula of calculating the water saturation of a reservoir by using the ratio of radial resistivity has been obtained in practical application to some extent. it shows that the new formula is not only of theoretical significance, but also of practical application significance, and is worth further popularizing.
Abstract: The resistivity response equation of sandstone is the most important basis for well logging interpretation to determine the water saturation of reservoir, but the Archie formula and its derivations are all empirical formulas, and the test error by experimental data is more than 20%. Because the coincidence rate of the log interpretation of low resi...
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Hydrocarbon Spill Management Through Leak Localization in Natural Gas Pipeline
Anthony Chemazu Igbojionu,
Ubanozie Julian Obibuike,
Mathew Udechukwu,
Chioma Deborah Mbakaogu,
Stanley Toochukwu Ekwueme
Issue:
Volume 8, Issue 6, November 2020
Pages:
137-142
Received:
21 September 2020
Accepted:
6 October 2020
Published:
16 November 2020
Abstract: It is important that leaks are detected early in pipelines. The need for prompt and accurate leak detection becomes more crucial when the pipeline content is gaseous. Remedial actions require that the leak location be determined in any leak incidence. Accurate leak localization will not only save cost but will enhance remedial actions such as replacement and repairs of damaged pipeline sections, clean-up of affected ecological systems and direct inspection of degree of damage. This information will aid in understanding the causes and effects of the leak. This paper presents a mathematical model for determination of the location of leak in a natural gas pipeline. The mathematical approach employed a mass balance approach to the modification of the Weymouth’s gas transportation equation in a horizontal natural gas pipeline. The pipeline under consideration was divided into two sections at the advent of leak. Before the leak point the pipeline cross section is represented as the upstream section while the downstream represents the section ahead of the leak point. The mathematical model herein was developed with reference to the downstream section of the pipeline. The results showed good accuracy with other leak location models available in literature and was also verified to be correct and within acceptable error limits when compared with actual field data.
Abstract: It is important that leaks are detected early in pipelines. The need for prompt and accurate leak detection becomes more crucial when the pipeline content is gaseous. Remedial actions require that the leak location be determined in any leak incidence. Accurate leak localization will not only save cost but will enhance remedial actions such as repla...
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Development of Revenue Model for Optimum Gas Distribution and Utilisation in Nigeria
Kenneth Nduka,
Ubanozie Julian Obibuike,
Mathew Udechukwu,
Chioma Deborah Mbakaogu,
Anthony Chemazu Igbojionu,
Stanley Toochukwu Ekwueme
Issue:
Volume 8, Issue 6, November 2020
Pages:
143-150
Received:
21 September 2020
Accepted:
6 October 2020
Published:
16 November 2020
Abstract: The emergence of gas projects have increased the demand for natural gas. Producers of natural gas are faced with the challenge of gas distribution to users. At this point, in order to maintain demand and supply, a model is required to determine optimum distribution of gas. In this paper, models are developed for optimum gas distribution and utilisation in Nigeria. The models seek to evaluate the monetary returns accruable from the utilisation of gas resources produced in Nigeria for domestic uses. Many outlets were suggested for domestic utilisation of gas produced in Nigeria. These gas utilisation and monetization outlets were proved to have viability and competitive advantage when compared with the sales of the gas abroad. The domestic gas supply revenue formula was formulated by considering the quantity of gas each gas producer will produce, the demand of the gas locally, the price stipulated for the gas in order to ensure profitability when sold locally, the penalty price for companies willing to flare and not supply their gas, the gas deficiency price etc. The revenue formula helps the government and gas producers to determine the extent of financial returns accruable from the sale of gas for domestic utilisation. The Model is sufficient to help the government make necessary decisions and plans as regarding domestic gas aggregation in Nigeria.
Abstract: The emergence of gas projects have increased the demand for natural gas. Producers of natural gas are faced with the challenge of gas distribution to users. At this point, in order to maintain demand and supply, a model is required to determine optimum distribution of gas. In this paper, models are developed for optimum gas distribution and utilisa...
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Oil-Water Emulsion Separation Using Nanoparticle-Coated Polystyrene Membrane
Chioma Deborah Mbakaogu,
Ngozi Claribelle Nwogu,
Nkemakolam Chinedu Izuwa,
Stanley Toochukwu Ekwueme
Issue:
Volume 8, Issue 6, November 2020
Pages:
151-156
Received:
21 September 2020
Accepted:
5 October 2020
Published:
27 November 2020
Abstract: The demand for membranes have increased enormously in the last decades due to increased applicability in many industrial activities. In the oil and gas industry, filtration membranes gain popularity over other types of membranes due to their usage in separation of oil-water emulsion using microfiltration and/or ultrafiltration techniques. Researchers have geared interest in the development of better performance membranes aimed at improving the efficiency of separation and antifouling properties. Developments in nanotechnology has made available nanoparticles which are used to further enhance the properties and performance of membranes, adding credence to membrane usage in emulsion separation. In this work, Polystyrene membrane of size 0.1µm is enhanced by coating with Aluminium oxide nanoparticle for improve fouling resistance properties and separation efficiency. Experiments were conducted in separation of oil-water emulsion using the prepared composite membrane system. Results show that the membrane system yields 97.86% and 97.54% efficiency in terms of oil rejection for a pressure application of 60% stroke and 80% stroke respectively while the permeation fluxes are 2.433 ml/cm2-min and 1.944 ml/cm2-min for 80% stroke and 60% stroke pressure applications respectively. The results reveal that increase in pressure has less effect in the membrane efficiency. The application of aluminum oxide coating increased the efficiency of the membrane and reduced its fouling characteristics.
Abstract: The demand for membranes have increased enormously in the last decades due to increased applicability in many industrial activities. In the oil and gas industry, filtration membranes gain popularity over other types of membranes due to their usage in separation of oil-water emulsion using microfiltration and/or ultrafiltration techniques. Researche...
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Drillstring Buckling Prediction and Its Impact on Tool-Joint Effects in Extended Reach Wells
Issue:
Volume 8, Issue 6, November 2020
Pages:
157-166
Received:
7 December 2020
Accepted:
28 December 2020
Published:
4 January 2021
Abstract: The mechanism of buckling has been extensively studied in pipes and tubings. But these studies more often has been restricted to continuous or straight body pipes. In reality most pipes and other drillstring elements have end couplings or connections known as tool joint. Tool joint presence changes the annular geometry, hydraulics and stress distribution of the pipe or tubulars in the wellbore. Modelling drillstring in highly deviated wells with no regards to the tool joint effects has been a major source of error in many drilling mechanics analysis. This has often led to misleading information on buckling and bending of the pipe which could lead to drilling and completion problems and costly well interventions. Thus it becomes necessary to model tool joint effect in the drillstring as it is subjected to downhole forces and stresses. In this study, emphasis is made on the determination of tool joint effect on pipe buckling for highly deviated extended reach wells (ERWs). WellPlan T&D spreadsheet software was used for the simulation. The simulation was runned for pipe with tool joint and the same pipe with the tool joints removed. Results show that jointed pipes has similar buckling behaviour with continuous straight body pipes with buckling starting from sinusoidal buckling mode and gradually entering the helical buckling mode for both types of pipes. Furthermore, result revealed that tool joint presence increases the critical buckling force by an average of 28.9% for helical as well as (AWA) sinusoidal buckling modes.
Abstract: The mechanism of buckling has been extensively studied in pipes and tubings. But these studies more often has been restricted to continuous or straight body pipes. In reality most pipes and other drillstring elements have end couplings or connections known as tool joint. Tool joint presence changes the annular geometry, hydraulics and stress distri...
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Research and Experiment on Smart Remote Testing and Regulating Technology for Separate Injection
Zhang Peng,
Wu Zhenghua,
Fang Zhigang,
Li Nanxing,
Wang Yuming,
Pu Chunsheng
Issue:
Volume 8, Issue 6, November 2020
Pages:
167-172
Received:
19 November 2020
Accepted:
1 December 2020
Published:
22 January 2021
Abstract: The smart remote testing and regulating separate injection technology is developed in light of the problem of unable to satisfy the requirement of refined zonal water injection due to failing to adaptively control the volume of injection per the variation of formation pressure for fixed nozzle injection allocation model adopted by bridge eccentric separate injection technology as well as problems of large size of matching testing and regulating equipment & tools, retrieving testing & regulating approaches constrained by well deviation and injection water quality plus pressure unable to be accurately measured due to high testing and regulating frequencies etc. The remote zonal water volume control, downhole constant flow injection and real time monitoring of the wellhead flow rate, pressure and temperatures are realized by the synergy of downhole water distributor, surface control and data acquisition unit as well as the remote desktop communication unit. In the mean time, the downhole zonal flow rate and pressure data are transmitted to the control room in remote manner to realize the wellhead unmanned operation. It is indicated by the field experiment that this technology features simple process string, reliable and safe construction and testing & regulating, sound adaptability for highly deviated and horizontal wells, which lays solid foundation for the refined low cost lean management in terms of zonal water injection wells in high water cut oilfields.
Abstract: The smart remote testing and regulating separate injection technology is developed in light of the problem of unable to satisfy the requirement of refined zonal water injection due to failing to adaptively control the volume of injection per the variation of formation pressure for fixed nozzle injection allocation model adopted by bridge eccentric ...
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